Barcelona have confirmed that a thigh injury forced Javier Mascherano to miss Sunday's 4-1 win over Las Palmas in La Liga, but not how long he will be sidelined for.
Mascherano was named in the starting lineup, but was forced to withdraw from the game just 20 minutes before kickoff after experiencing some discomfort during the warm-up.
Barca B defender Marlon Santos took his place in the side, making his first league appearance for the club since joining on loan from Fluminense last summer.
"Tests carried out on Monday confirm that Mascherano has a slight injury to his right thigh," a statement from the Catalan club said. "His recovery will dictate when he can return."
As well as Mascherano, Barcelona were without Gerard Pique, Sergi Roberto, Aleix Vidal and Jeremy Mathieu for the match at the Estadio Gran Canaria, leaving them short in defence.
However, Roberto will return from suspension for this weekend's final league game of the season at Camp Nou against Eibar, while Pique is expected to recover from a virus which saw him spend the weekend in hospital.
After the Eibar game -- which Barca must win, while hoping Real Madrid slip up in one of their remaining two league games, to clinch a third successive title -- the Blaugrana face Alaves in the Copa del Rey final the following weekend.
If Mascherano doesn't recover for either of those games, it may represent another chance for Marlon to gain more first team experience.
"I was a bit nervous at the start, I could feel it in my stomach, but I managed to control my emotions," he said after playing 90 minutes against Las Palmas.
"I had to give my best. I work hard all week for chances like this and I think I was ready. It was a unique opportunity."
Barca have an option to sign Marlon at the end of the campaign and are expected to do so in a deal which would be worth €5.5 million, although they would only have to pay €2m due to a payment they previously made to Fluminense.